I just had my fibreglass pool resurfaced with ecofinish. As the pool was filling up very small bubbles were appearing on all the surfaces under water. I was slowly filling up the pool with a regular garden hose from the house. There are thousands of these very small bubbles clinging to the surface. When you wipe them away it looks like dirt being swept from the surface with the pool brush. No chemicals were added to the pool and eventually they come back.